This invention generally relates to a portable manufacturing tool for connecting plumbing fittings to hardened hose ends and, in particular, this invention provides a means for forming an overlapping joint among piping members by roll forming an annular crimp into the circumference of the joint.
While it will be understood that the present invention may have a wide variety of useful and commercial applications, one such application is in the manufacture of large dynamo-electric machines of the type shown in U.S. Pat. No. 3,755,702 to Willyoung issued Aug. 28, 1973. The dynamoelectric machine shown in that patent includes a liquid cooled stator 19. In a single pass machine, liquid coolant (usually water) enters an inlet manifold ring 31, and then is transmitted to the individual stator bars through a plurality of hoses 26, exits the machine through a plurality of hoses 27 connected to an outlet manifold ring 35 for transport back to a reservoir for recirculation back to the inlet manifold ring. Such a machine might have on the average one hundred hoses. It is imperative that the hoses and connections be leak-proof and therefore rigorous testing standards are applied.
In the prior art method of manufacture, a hose was prefabricated with a fitting on each end. These fittings were then brazed to appropriate connection points from the headers to the stator bars. The brazing operation became the only feasible way of making the appropriate connections since the preformed hoses and fittings were not always matched to the realities of the distances between connection points. Thus brazing gave some latitude with respect to manufacturing tolerances. One reason for the prefabrication of fittings to the hose ends was that it was believed that a leak-proof connection between a hose end and a fitting could only be accomplished by using a large hydraulic stamping machine which would apply instantaneous circumferential pressure around the hose and the fitting to form a stamped joint. There is however, considerable disadvantage in the prior art as thus described. One disadvantage is that a brazing operation within the confines of the end winding system of a dynamoelectric machine can be described as cumbersome, at best, and near impossible under some circumstances. Another disadvantage is the risk of damage to the hose itself or the connection between the hose and fitting during the brazing operation.